Lionfish Stings – A Diver’s Nightmare

by Sue Endicott, MSN, RN:


If you saw a preview where a 15” fish weighing 2 pounds overwhelmed the oceans off the U.S., killing off native fish and disrupting the ecosystem, you might think this was a plug for a bad movie.  The truth is it isn’t… it’s reality.

All divers have heard about lionfish.  Once indigenous only to Indo-Pacific areas, they’re a growing threat to native fish and the environment in U.S. waters. Theories offer explanations for how they arrived here, including being blown in during hurricanes, but the more believable explanation is man played a part in their introduction by releasing this popular aquarium fish into the Atlantic Ocean.

This problem is complex.  Lionfish have no natural predators here, kill fish and crustaceans at an alarming rate and reproduce rapidly.  These factors combine to create one of the largest threats U.S. oceans have ever seen.  It is being called an epidemic.  To view how quickly lionfish have overwhelmed the U.S. and other areas from 1985-2015, click here.

Organizations including NOAA and The Reef Foundation have combined efforts to address this problem.  The Reef Foundation is working to fight this epidemic by tracking sightings, gathering information on behavior patterns, collecting lionfish and educating the public on the threat they pose to humans who come in contact with them.

The Threat

Lionfish are a threat to marine life and to divers as well.  Lionfish have venomous spines which cause painful wounds.  With the lionfish population increasing, the odds of getting stung increases as well.  Recreational divers frequenting areas with lionfish are at risk for not only being stung once, but repeatedly.  This is true for commercial divers as well, as the lionfish population is well established in the gulf region where a great deal of commercial diving takes place.  Initial exposure to the toxins from a lionfish sting will produce a very painful injury, and often there will be a mild localized or systemic allergic reaction associated with the sting.

Signs and symptoms

  • Severe pain
  • Redness, bruising, swelling


Prevention is the best treatment.  Stay aware of your surroundings and remember lionfish can sting after they are dead.  Have the supplies you need to care for a sting and should one occur get the person out of the water and treat the injury.

  • Wear Gloves! Personal safety is the highest priority
  • Administer pain medications
  • Administer Benadryl for mild allergic reactions
  • Immerse the wound in water as hot as the person can tolerate for 30 – 60 minutes and repeat as necessary as the toxins are neutralized by heat
  • Use forceps to remove pieces of spines and be careful not to squeeze the venom gland that may have broken off with the spine
  • Clean with soap and water
  • Apply antibiotic ointment
  • Cover loosely with gauze to prevent contamination
  • Do not tightly close the wound until evaluated by a physician
  • Seek follow-up medical attention
  • Consider updating tetanus

The Greater Threat – Anaphylaxis

Exposure to a lionfish sting may cause a mild allergic reaction.  The greater danger has to do with multiple exposures to the toxins.  Anaphylaxis is a severe, life-threatening reaction to a bee sting, food, or other substance.  It often does not occur the first time a person contacts the toxin, but after subsequent exposures.  There have been no known documented cases of true anaphylaxis associated with lionfish stings to date, but the potential for future cases remains high related to the odds of suffering an initial injury and repeated exposure.  When discussing treatment for lionfish injuries it would be remiss not to mention this possible complication so divers are prepared for what may be coming.

The only treatment for severe allergic reaction is epinephrine.  Because there are no documented cases of anaphylaxis yet, the chances of someone carrying epinephrine specifically for this type of injury are low.  All evidence points to it only being a matter of time, however, before we see anaphylactic reactions to lionfish stings.  The practice of individuals carrying epinephrine auto injectors in the future in case of lionfish stings may be as common as carrying them for bee stings or other known allergic reactions today.

Signs and Symptoms of Anaphylaxis

  • Difficulty breathing
  • Wheezing
  • Swelling of the lips or tongue
  • Panic or a sense of impending doom
  • Hives


  • Administer epinephrine
  • Seek immediate medical attention
  • Support breathing with oxygen and rescue breathing as necessary
  • Perform CPR as needed

Commercial Diving Implications

When considering implications for commercial divers related to repeated exposure to lionfish stings, and the possibility of severe allergic reaction, questions were raised as to how to treat divers who might be at depth in a diving bell, or in pressurized situations such as a hyperbaric chamber.  The concerns included whether or not an auto injector would remain intact in these pressurized environments since they are a syringe filled with a liquid medication.

Triton Diving conducted an important study to determine if the epinephrine auto injector would indeed remain intact in such environments.  The results proved it did not malfunction or release the medication prematurely due to the pressure.  The implications of this are enormous as those suffering from anaphylactic reactions can be treated in pressurized environments without delaying life-saving care.  This avoids having to make the decision to bring a diver rapidly to the surface to administer the drug, which would create an entirely new set of life-threatening issues.

The findings of this study, coupled with the growing threat of anaphylactic reactions from lionfish stings for both recreational and commercial divers, are what prompted Dive 1st Aid to add the epinephrine auto injector as an option to their current Lionfish Sting Kit.

Lionfish are here to stay and will continue to multiply.  Be aware, prepared and stay up to date on the research and treatment of these injuries.  Remember… an informed diver is a smarter, safer diver.

Until next time… dive safe and have fun!

Sue Endicott, MSN, RN
Director of Education
Dive 1st Aid

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